Nonnative species disrupt ecosystems by
a. increasing biodiversity
b. preventing the spread of disease
c. disrupting food chains
d. increasing the populations of native species

Nonnative species disrupt ecosystems by disrupting food chains. 

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass